<?php
/**
 * Copyright 2011 MaGdev
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *    * Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    * Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *    * The names of the authors may not be used to endorse or promote products
 *      derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @package      Mashape API-Documentor
 * @author       Marco Graetsch <info@magdev.de>
 * @copyright    2011 Marco Graetsch.development
 * @license      http://opensource.org/licenses/bsd-license.php New BSD License
 * @link         https://code.google.com/p/apidocumentor/
 */


/**
 * Abstract class for metadata readers
 *
 * @author magdev
 * @abstract
 */
abstract class Mashdoc_Metadata_Abstract implements SplObserver
{
	/** @var DOMDocument */
	protected $_dom = null;
	
	/** @var DOMXPath */
	protected $_xpath = null;
	
	/** @var array */
	protected $_validTags = array(
		'authorName', 'authorUrl', 'version',
		'license', 'title', 'description',
		'apiUrl', 'licenseUrl', 'component'
	);
	
	/** @var array */
	protected $_tags = null;
	
	
	/**
	 * Constructor
	 */
	public function __construct() {}
	
	
	/**
	 * Implementation of SplObserver::update()
	 *
	 * @param SplSubject $subject
	 * @see SplObserver::update()
	 */
	public function update(SplSubject $subject)
	{
		$this->setApiDocument($subject->getApiDocument());
	}
	
	
	/**
	 * Set the API document
	 *
	 * @param DOMDocument $dom
	 * @return Mashdoc_Metadata_Abstract
	 */
	public function setApiDocument(DOMDocument $dom)
	{
		$this->_dom = $dom;
		$this->_xpath = new DOMXPath($this->_dom);
		return $this;
	}
	
	
	/**
	 * Check if a tag is valid
	 *
	 * @param string $tag
	 */
	public function isValidTag($tag)
	{
		return in_array($tag, $this->_validTags);
	}
	
	
	/**
	 * Get a tag value
	 *
	 * @param string $tag
	 * @return string
	 */
	public function getTag($tag)
	{
		$tags = $this->getTags();
		if (isset($tags[$tag])) {
			return $tags[$tag];
		}
		return null;
	}
	
	
	/**
	 * Get all tags
	 *
	 * @return array
	 */
	public function getTags()
    {
        return $this->_tags;
    }
	
	
	/**
	 * Update metadata
	 *
	 * @param Mashdoc_Metadata_Interface $metadata
	 * @return Mashdoc_Metadata_Abstract
	 */
	public function updateMetadata(Mashdoc_Metadata_Interface $metadata)
	{
	    if (is_null($this->_tags)) {
	        $this->getTags();
	    }
	    
	    if ($updateTags = $metadata->getTags()) {
    	    foreach ($updateTags as $tag => $value) {
    	        $this->_setTag($tag, $value);
    	    }
	    }
		return $this;
	}
	
	
	/**
	 * Magic method for getters
	 *
	 * @param string $method
	 * @param array $args
	 * @return string
	 * @throws BadMethodCallException
	 * @return Mashdoc_Metadata_Abstract
	 */
	public function __call($method, $args)
	{
		$tag = lcfirst(str_replace('get', '', $method));
		if (!$this->isValidTag($tag)) {
			throw new BadMethodCallException('Invalid tag: '.$tag, Mashdoc::E_INVALID_TAG);
		}
		if ($method[0] === 'g') {
    		return $this->getTag($tag);
		} else {
		    throw new BadMethodCallException('Method call must be named setXX or getXX', Mashdoc::E_UNKNOWN_METHOD);
		}
		return $this;
	}
	
	
	
	/**
	 * Get the tags as JSON
	 *
	 * @return JSON
	 */
	public function __toString()
	{
	    $tags = $this->getTags();
	    if (!$tags) {
	        $tags = array();
	    }
	    return json_encode($tags, JSON_FORCE_OBJECT);
	}
	
	
    /**
     * Set a tag value
     *
     * @param string $tag
     * @param string $value
     * @param boolean $keep
     */
    protected function _setTag($tag, $value, $keep = false)
    {
        if ($this->isValidTag($tag)) {
            if (is_null($this->_tags)) {
                $this->_tags = array();
            }
            $value = trim($value);
            
            if (!$value && isset($this->_tags[$tag])) {
                unset($this->_tags[$tag]);
                return;
            }
            
            if ($tag == 'component') {
                $value = str_replace(' ', '+', $value);
            }
            if (isset($this->_tags[$tag]) && $keep) {
                return;
            }
            $this->_tags[$tag] = $value;
            
            if ($tag == 'title') {
                $this->_setTag('component', $value, true);
            }
            if ($tag == 'component') {
                $this->_setTag('apiUrl', 'http://www.mashape.com/apis/'.$value, true);
            }
        }
    }
}